Coaxial tube solar heater with nighttime cooling

ABSTRACT

Disclosed is a solar water-heating-and-cooling system ( 20 ) that included a collector array panel ( 32, 36 ) having thermosyphon coaxial heating/cooling tubes ( 52 ). The disclosed system ( 20 ) avoids damaging the collector array panel ( 32, 36 ) by filling the tubes ( 52 ): 1. only when environmental conditions ensure that damage won&#39;t occur,—and/or 2. using a filling method that ensures that damage won&#39;t occur. Thermosyphon coaxial heating/cooling tubes ( 52 ) disclosed herein may be open both at their upper and lower ends. Tubes ( 52 ) that are open at their, lower end enables capturing radiative cooling of liquid present within the tubes ( 52 ). A cold water storage tank ( 46 ) and cold radiator array ( 48 ) included in the water-heating-and-cooling system ( 20 ) permits preserving and using the radiative ‘cooling. Also disclosed are coaxial tubes ( 104, 106 ) that enable simpler and easier installation of the system ( 20 ), and also provide a less architecturally intrusive system ( 20 ).

TECHNICAL FIELD

This disclosure relates generally to solar water-heating-systems, andmore specifically to an improved coaxial tube solarwater-heating-and-cooling-system capable of providing reliable heating,and, when warranted, cooling.

BACKGROUND ART

U.S. Pat. No. 6,014,968 entitled “Tubular Heating-Pipe SolarWater-Heating-System With Integral Tank” that issued Jan. 18, 2000, on apatent application filed in the name of Siang Teik Teoh (“the '968patent”) discloses a solar water-heating system having collector corethat includes a plurality of hollow heating-pipes. Each heating-pipe hasa longitudinal axis and an interior that is surrounded by an outer wall.When assembled into the collector core of the solar water-heatingsystem, the heating-pipes are aligned substantially parallel to eachother, and in use are adapted to be inclined to the horizontal. Thus,when in use each of the heating-pipes has an open upper end that iselevated above the heating-pipe's closed lower end. The open upper endof the heating-pipes disclosed in the '968 patent extend directly to,open into, and communicate directly with:

-   -   1. a lower level of a hot-water storage-tank; or    -   2. a lower portion of another the solar water-heating-panel.

Each of the hollow heating-pipes has an outer wall that surrounds ahollow cooler-water return-pipe. The cooler-water return-pipe withineach of the heating-pipes has an internal cross-sectional area that isapproximately equal to one-third (⅓) to one-half (½) of an internalcross-sectional area enclosed by the surrounding heating-pipe's outerwall. The cooler-water return-pipe within each of the heating-pipes alsohas a length that is slightly longer than a length of the outer wall ofthe heating-pipe. Thus, the open upper end of the cooler-waterreturn-pipe extends beyond the open upper end of the heating-pipe'souter wall. In this way the upper end of the cooler-water return-pipeextends into and communicates directly with:

-   -   1. the lower level of a hot-water storage-tank; or    -   2. the lower portion of another the solar water-heating-panel.        A lower end of each cooler-water return-pipe is perforated so        fluid may flow outward from within the lower end of each        cooler-water return-pipe toward the surrounding outer wall of        the heating-pipe.

Preferably, the solar water-heating system disclosed in the '968 patentincludes a transparent cover, usually made of glass, that is disposedimmediately adjacent to and shields the heating-pipes. The solarwater-heating system disclosed in the '968 patent when assembled withevacuated glass thermosyphon coaxial heating tubes exhibits the highestthermal efficiencies of all presently known solar water-heating systems.

Existing solar hot water panels are susceptible to mechanical damage ifwater in the heating-pipes freezes and cracks the heating-pipes. Priorsystems have addressed this problem through an indirect system in whichsolar radiation heats an antifreeze solution in heating-pipes, or isheated at a condenser portion of heat pipes. The hot antifreeze solutionthen circulates through a heat exchanger located in the hot-waterstorage-tank to heat the water. This type of solar water-heating-systemis inefficient since the water is only indirectly heated by theantifreeze solution. Consequently, this indirect solarwater-heating-panel system heats less water than a direct solarwater-heating-system in which the water being heated circulates throughheating-pipes. Moreover, indirect solar water-heating panel systems aremore expensive and complicated than direct solar water-heating-systems,and require maintenance including regular topping up of anyintermediate-working liquid antifreeze solution if such is used.

Another problem sometimes experienced with prior water filled solar hotwater panels occurs if the hot-water storage-tank's and heating-pipes'water supply is accidentally interrupted for a few weeks. During thewater supply interruption the hot-water storage tank and heating-pipescan boil dry. After the hot-water storage-tank and heating-pipes boildry, restoring the water supply to the solar hot water panel on a hotday introduces cold water swiftly into hot heating-pipes. Swiftintroduction of cold water into hot heating-pipes can cause theheating-pipes to bend to such an extent that they can shatter either:

-   -   1. a glass tube of an evacuated thermosyphon coaxial heating        tube that surrounds the solar hot water panel's outer wall and        hollow cooler-water return-pipe; or    -   2. an immediately adjacent transparent glass cover.

DISCLOSURE

The present disclosure provides a very high efficiency collector arraypanel for an improved solar water-heating-and-cooling-system. The veryhigh efficiency collector array panel includes coaxial heating tubesthat are similar to those disclosed:

-   -   1. in United States Statutory Invention Registration US H2231 H        entitled “Tubular Heating-Pipe Solar Water-Heating-System With        Integral Tank” that was published on Aug. 4, 2009, on an        application filed in the name of Siang Teik Teoh (“the H2231        SIR”), and also    -   2. in the '968 patent.        However, the solar water-heating-and-cooling-system disclosed        herein offers enhanced resistance to thermal shock damage that        may result from unintentionally introducing cold water or cold        heating fluid into empty, hot heating tubes on a sunny day where        the heating tubes have remained exposed to solar radiation prior        to filling.

An object of the present disclosure is to provide an efficient solarwater-heating-and-cooling-system.

Yet another object of the present disclosure is to provide a highlyefficient coaxial heating tube solar water-heating-and-cooling-systemthat exhibits enhanced resistance to thermal shock damage.

Yet another object of the present disclosure is to provide a solarwater-heating-and-cooling-system that advantageously captures nighttimeradiative cooling capability of coaxial solar heating tube collectorsthat present conventional solar water-heating-systems fail to utilize.

Yet another object of the present disclosure is to provide a solarwater-heating-and-cooling-system that is simpler and easier to install.

Yet another object of the present disclosure is to provide a solarwater-heating-and-cooling-system that less architecturally intrusive.

Yet another object of the present disclosure is to provide a solarwater-heating-and-cooling-system that is less visible.

Briefly, in one aspect this disclosure includes a solar heating systemthat has at least one collector array panel. The collector array panelis adapted for being located on a sloping roof of a building, andincludes a plurality of thermosyphon heating tubes. The solar heatingsystem also includes a liquid source adapted for supplying liquid to thecollector array panel's heating tubes. Finally, the solar heating systemincludes a cut-off valve coupled both to:

-   -   1. a mains supply for receiving liquid therefrom; and    -   2. the liquid source.        Configured in this way, the cut-off valve automatically blocks        liquid received by the cut-off valve from the mains supply from        filling the collector array panel's heating tubes whenever such        filling could damage the collector array panel.

In another aspect this disclosure includes a solar heating system thathas at least one collector array panel. The collector array panel isadapted for being located on a sloping roof of a building, and includesa plurality of thermosyphon heating tubes, each heating tubes being openat a lower end thereof. The solar heating system also includes anintermediate manifold coupled to lower, ends of the collector arraypanel's heating tubes for supplying liquid thereto. The solar heatingsystem further includes a liquid source adapted for supplying liquid viathe intermediate manifold to lower ends of the collector array panel'sheating tubes. Finally, the solar heating system includes a pressurereducing valve that is:

-   -   1. coupled between a mains supply and the liquid source; and    -   2. set at a low pressure and flow rate.        Configured in this way the pressure reducing valve limits a rate        at which the collector array panel's heating tubes slowly fill        with liquid thereby preventing filling of the heating tubes from        damaging the collector array panel.

In yet another aspect this disclosure includes a solarheating-and-cooling system that has at least one collector array panel.The collector array panel is adapted for being located on a sloping roofof a building, and includes a plurality of thermosyphon heating/coolingtubes. Each heating/cooling tube is open both:

-   -   1. at an upper end of the collector array panel; and    -   2. at a lower end thereof.        The disclosed solar heating-and-cooling system also includes a        heated-liquid chamber that is located above the collector array        panel's upper end. The heated-liquid chamber is coupled to the        collector array panel's heating tubes for receiving hot liquid        warmed within the collector array panel. Finally, the solar        heating-and-cooling system includes a cold liquid storage tank        that is located below the collector array panel's lower end. The        cold liquid storage tank is coupled to the collector array        panel's heating/cooling tubes for receiving cool liquid chilled        within the collector array panel.

In yet another aspect this disclosure includes a solar cooling systemthat has at least one collector array panel adapted for being located ona sloping roof of a building. The collector array panel includes aplurality of thermosyphon cooling tubes each of which is open at a lowerend of the collector array panel. Finally, the solar cooling systemincludes a cold liquid storage tank located below the collector arraypanel's lower end. The cold liquid storage tank is coupled to thecollector array panel's cooling tubes for receiving cool liquid chilledwithin the collector array panel.

In a final aspect this disclosure includes a solar heating system thathas at least one collector array panel adapted for being located on asloping roof of a building. The collector array panel includes aplurality of thermosyphon heating tubes, each heating tube being open atan upper end of the collector array panel. The collector array panelalso includes an upper manifold located at the collector array panel'supper end that exchanges liquid with the collector array panel's heatingtubes. The solar heating system further includes a heated-liquid chamberlocated above the collector array panel's upper end that receives hotliquid warmed within the collector array panel. Finally, the solarheating system includes a heated-liquid coaxial tube that conductsliquid, via the upper manifold, between collector array panel's heatingtubes and the heated-liquid chamber.

These and other features, objects and advantages will be understood orapparent to those of ordinary skill in the art from the followingdetailed description of the preferred embodiment as illustrated in thevarious drawing figures.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1A is a partially cut, away perspective view of a solarwater-heating-and-cooling-system including a collector array panel, thesolar water-heating-and-cooling-system providing both heating andcooling in accordance with the present disclosure.

FIG. 1B is a partially cut away perspective view of a hot water storagetank and a portion of a collector array panel resting on a roof of ahouse taken along the line 1B-1B in FIG. 1A.

FIG. 2 is a diagram illustrating arrangement of FIGS. 2A-2E into across-sectional elevational view of the entire solarwater-heating-and-cooling-system depicted in FIG. 1A when heating waterduring daytime.

FIG. 2A is a cross-sectional elevational view of a hot water storagetank included in the solar water-heating-and-cooling-system depicted inFIG. 1A when heating water during daytime.

FIG. 2B is a cross-sectional elevational view of a glazed collectorarray panel included in, the solar water-heating-and-cooling-systemdepicted in FIG. 1A when heating water during daytime.

FIG. 2C is a cross-sectional elevational view of an intermediatemanifold included in the solar water-heating-and-cooling-system'scollector array panel depicted in FIG. 1A when heating water duringdaytime.

FIG. 2D is a cross-sectional elevational view of a cold water storagetank included in the solar water-heating-and-cooling-system depicted inFIG. 1A when heating water during daytime.

FIG. 2E is a cross-sectional elevational view of a cooling radiatorincluded in the solar water-heating-and-cooling-system depicted in FIG.1A when heating water during daytime, and a support frame therefor.

FIG. 3 is a diagram illustrating arrangement of FIGS. 3A-3E into across-sectional elevational view of the entire solarwater-heating-and-cooling-system depicted in FIG. 1A when cooling waterduring nighttime.

FIG. 3A is a cross-sectional elevational view of the hot water storagetank included in the solar water-heating-and-cooling-system depicted inFIG. 1A when cooling water during nighttime.

FIG. 3B is a cross-sectional elevational view of the glazed collectorincluded in the solar water-heating-and-cooling-system depicted in FIG.1A when cooling water during nighttime.

FIG. 3C is a cross-sectional elevational view of the intermediatemanifold included in the solar water-heating-and-cooling-system'scollector array panel depicted in FIG. 1A when cooling water duringnighttime.

FIG. 3D is a cross-sectional elevational view of the cold water storagetank included in the solar water-heating-and-cooling-system depicted inFIG. 1A when cooling water during nighttime.

FIG. 3E is a cross-sectional elevational view of the cooling radiatorincluded in the solar water-heating-and-cooling-system depicted in FIG.1A when cooling water during nighttime, and the support frame therefor.

FIG. 4A is a cross-sectional elevational view of the hot water storagetank included in the solar water-heating-and-cooling-system taken alongthe line 4-4 in FIG. 1A when filled with water.

FIG. 4B is a cross-sectional elevational view of the hot water storagetank included in the solar water-heating-and-cooling-system taken alongthe line 4-4 in FIG. 1A if the solar water-heating-and-cooling-systemhas boiled dry.

FIG. 5 is a cross-sectional elevational view of the glazed collectorarray panel included in the solar water-heating-and-cooling-system takenalong the line 5-5 in FIG. 1A.

FIG. 6 is a cross-sectional elevational view of the intermediatemanifold included in the solar water-heating-and-cooling-system'scollector array panel taken along the line 6-6 in FIG. 1A.

FIG. 7 is a cross-sectional elevational view of the unglazed collectorarray panel included in the solar water-heating-and-cooling-system takenalong the line 7-7 in FIG. 1A.

FIG. 8 is a partially cut away perspective view of the intermediatemanifold when operating to heat water during daytime that is included inthe solar water-heating-and-cooling-system's collector array panel ofFIG. 1A.

FIG. 9 is a partially cut away perspective view of the intermediatemanifold when operating to cool water during nighttime that is includedin the solar water-heating-and-cooling-system's collector array panel ofFIG. 1A.

FIG. 10 is a partially cut away perspective view of an alternativeembodiment of the intermediate manifold that has enlarged diameter pipeswhen operating to heat water during daytime that may be included in thesolar water-heating-and-cooling-system's collector array panel of FIG.1A replacing the intermediate manifold depicted in FIGS. 8 and 9.

FIG. 11 is a partially cut away perspective view of an alternativeembodiment a solar water-heating-and-cooling-system including a singleconnection collector array panel, the solarwater-heating-and-cooling-system in accordance with the presentdisclosure providing both heating and cooling.

FIG. 12 is a partially cut away perspective view of an upper manifoldincluded in the single connection collector array panel depicted in FIG.11 during daytime heating.

FIG. 13 is a perspective view of an alternative embodiment solarwater-heating-and-cooling-system including a single connection collectorarray panel, the solar water-heating-and-cooling-system in accordancewith the present disclosure providing only heating.

FIG. 14 is a partially cut away perspective view of a hinged-openinglower tube holder, that receives lower ends of heating/cooling tubesincluded in the collector array panel depicted in FIG. 13 when used onlyfor heating.

FIG. 15 is a plan cross-sectional view of the hinged-opening lower tubeholder that receives lower ends of heating/cooling tubes included in thecollector array panel depicted in FIG. 13 indicating movement of abottom tube holder responsive to the heating/cooling tubes' expansionand contraction when used only for heating.

FIG. 16 is a cut-away cross-sectional view of yet another alternativeembodiment solar, water-heating-and-cooling-system that includes a pairof glazed collector array panels each of which rests on a different roofsurface that abut each other at a ridge of the roof located beneath thehot water storage tank and are connected in parallel to the cold waterstorage tank.

BEST MODE FOR CARRYING OUT THE DISCLOSURE

Drawing FIGS. 1A-10 included in this patent application, in conjunctionwith the disclosure respectively of the '968 patent and of the H2231SIR, provide sufficient detail information to permit assembling andusing various solar water-heating-and-cooling systems disclosed herein.The '968 patent and the H2231 SIR are both hereby incorporated byreference as though fully set forth here.

If a solar water-heating system of the type disclosed in the '968 patentand the H2231 SIR having evacuated glass thermosyphon coaxial heatingtubes experience dry stagnation, temperature inside evacuatedthermosyphon coaxial heating tube can rise to 250° C. When such hot,empty evacuated thermosyphon coaxial heating tubes fill from the topdown as generally occurs, the speed of liquid flowing down through hotheating tubes cannot be controlled because gravity drives the coldliquid's downward trickle flow. If such a solar water-heating system isempty and thermosyphon coaxial heating tubes remain exposed to solarradiation for one or two hours on a hot sunny day, upon filling thecoaxial heating tubes with cold water or heating liquid from the top thetubes exhibit slight temporary arcing or bending. Arcing or bendingoccurs because the cold liquid trickling down the hot heating tubescauses each heating tube's lower half cross-section to contract suddenlywhile the upper half cross-section remains dry and hot and thereforeuncontracted. Such sudden uneven contraction across the tube'scross-section urges the heating tubes to arc upwards slightly and inextreme cases to contact and even shatter an adjacent transparent glasscover or a surrounding evacuated glass tube. The H2231 SIR addressesthis problem by utilizing corrugated heating tubes which are moreflexible and thus less prone to exert any strong force on the enclosingglass tube or glass cover if the inner corrugated tube were to arcsslightly. However, to avoid damage even corrugated heating tubes thatexhibit lesser arcing still must be spaced further away from the glasstube or glass cover. Spacing corrugated heating tubes further away fromthe glass cover restricts heating tube diameter. The solarwater-heating-and-cooling system disclosed herein avoids the extremeheating tube bending caused by the cold water or heating liquidtrickling down the hot heating tube by filling tubes through a manifoldor tank located below the tubes, and not from above as disclosed in the'968 patent and in the H2231 SIR.

Some flat plate tube and fin solar thermosyphon solar water-heatingsystems such as that disclosed in U.S. Pat. No. 4,084,578 entitled“Solar Water Heater of Natural Circulation Type,” that issued Apr. 18,1978, on a patent application filed in the name of Toshihiro Ishibashi(“the '578 patent”), also disclose filling the collector from below.However, thermosyphon solar water-heating systems of the type depictedin the '578 patent are less thermally efficient in comparison with asystem having evacuated glass coaxial heating tubes when used in thesolar water-heating systems disclosed both in the '968 patent and in theH2231 SIR. Consequently, under dry stagnation thermosyphon solarwater-heating systems such as that disclosed in the '578 patent do norreach as high a temperature as that exhibited by collector array panelshaving evacuated glass coaxial heating tubes. Avoiding the extremebending of evacuated thermosyphon coaxial heating tubes during cold fillon a hot day by controlling the rate of cold liquid inflow upward intothe collector array panel's coaxial heating tubes as disclosed hereinpermits safely locating the solar water-heating-and-cooling system'scoaxial thermosyphon heating tubes closer to the glass tube or glasscover thereby increasing solar collection efficiency.

Furthermore, the solar water-heating-and-cooling system disclosed hereinpreferably also preheats infilling liquid by:

-   -   1. first passing it through a heat-exchange-coil located in a        hot water storage tank; and    -   2. then initially filling coaxial thermosyphon heating tubes of        a lower, unglazed collector array panel;        before liquid rises slowly into the coaxial thermosyphon heating        tubes of an upper, glazed collector array panel. Filling the        coaxial thermosyphon heating tubes of the upper, glazed        collector array panel in this way reduces temperature difference        between liquid and hot coaxial thermosyphon heating tubes of the        upper, glazed collector array panel.

Moreover, the solar water-heating-and-cooling system disclosed hereinmay advantageously include a pressure reducing valve set to very lowpressures of 5 psi or less and a flow control valve, both of whichconnect in series along a cold water or liquid supply pipe. Includingsuch a pressure reducing valve and flow control valve regulates the flowrate of water or liquid filling the collector array panel's coaxialthermosyphon heating tubes so the liquid's level rises slowly in theglazed heating tubes thereby avoiding sudden extreme arcing or bucklingof the heating tubes.

The slow infill flow rate does not affect the flow rate or pressure ofhot water drawn off to hot showers or for other uses because hot wateris drawn from the solar water-heating-and-cooling system disclosedherein through a pressurized heat-exchange-coil, depicted in FIGS. 2A,3A 4A and 4B, that is immersed in the hot water storage tank. Thus, theflow rate or pressure of hot water drawn off for hot showers or otheruse is from the mains water supply or household water pump, andtherefore the hot water pressure can be set to any desired value.

FIG. 1A depicts an overall view of the solar water-heating-and-coolingsystem referred to by the general reference designation 20.Specifically, FIG. 1A illustrates a portion of the solarwater-heating-and-cooling system 20 installed over roof tiles 22 of asloping roof 24 of a single story building 26. Included in the solarwater-heating-and-cooling system 20 depicted in FIG. 1A are:

-   -   1. an optional unglazed collector array panel 32;    -   2. a thermally insulated intermediate manifold 34; and    -   3. a glazed collector array panel 36 of the solar        water-heating-and-cooling system 20.        A thermally insulated hot-water storage-tank 38 of the solar        water-heating-and-cooling system 20 rests on a ridge 42 of the        roof 24 as better illustrated in FIG. 2. A cold water storage        tank 46 and a cold radiator array 48 of the solar        water-heating-and-cooling system 20 are located below the roof        24 inside the building 26. For the solar        water-heating-and-cooling system 20 depicted in FIGS. 1A, 1B and        2, thermosyphon coaxial heating tubes included in the unglazed        and glazed collector array panels 32, 36 respectively extend        directly into the hot-water storage-tank 38, the intermediate        manifold 34, and the cold water storage tank 46. Resting on the        sloping roof 24, hotter liquid in the thermosyphon coaxial        heating tubes of the unglazed and glazed collector array panels        32, 36 rises toward the hot-water storage-tank 38, and cooler        liquid in the hot-water storage-tank 38 descends through the        thermosyphon coaxial heating tubes towards the bottom of the        unglazed and glazed collector array panels 32, 36.

FIGS. 5-7 provide differing cross-sectional views of thermosyphoncoaxial heating/cooling tubes 52 included in the unglazed collectorarray panel 32 and glazed collector array panel 36. In the illustrationof FIG. 5, evacuated glass tubes 54 of the glazed collector array panel36 enclose preferably corrugated outer heating/cooling tubes 56 that inturn enclose inner heating/cooling tubes 58. For the unglazed and glazedcollector array panels 32, 36 included in the solarwater-heating-and-cooling system 20 depicted in FIGS. 1A, 2 and 2Bthrough 2C, the outer and inner tubes 56, 58 are open both at the upperend of the unglazed and glazed collector array panels 32, 36 and at thelower end thereof. All that appears in FIG. 6's cross-sectional view ofthe intermediate manifold 34 are ends of the outer and inner tubes 56,58 that are included in the glazed collector array panel 36. Similarly,FIG. 7's view of the unglazed collector array panel 32, that lacks theglass tubes 54, depicts only cross-sections of the outer and inner tubes56, 58. Also depicted in FIGS. 5 and 7 is a highly reflective surface62, such as reflective aluminum foil or other reflective metal sheet,that is corrugated so each of the thermosyphon coaxial heating/coolingtubes 52 lies at a corrugation's focus.

The illustration of FIG. 5 also depicts an optional transparentprotective cover 63, preferably made from a sheet of acrylic materialsuch as Perspex® or from a sheet of tempered glass, that spans acrosslateral edges of the glazed collector array panel 36 above thethermosyphon coaxial heating/cooling tubes 52. Adding the transparentprotective cover 63 to the glazed collector array panel 36 increases itsresistance to hail damage. Alternatively, while exhibiting a lesserthermal performance than a glazed collector array panel 36 having vacuumglass tubes 54, a less expensive glazed collector array panel 36 can beassembled by omitting the vacuum glass tubes 54 and including thetransparent protective cover 63.

The cross-sectional views of FIGS. 2 and 2A-2E illustrate the solarwater-heating-and-cooling system 20 when being heated during daytimewhen thermosyphon coaxial heating/cooling tubes 52 included in unglazedand glazed collector array panels 32, 36 absorb radiation from the sunthrough absorptive black coated surfaces to heat water therein asdescribed in the '968 patent and the H2231 SIR. During daytime waterinside outer heating/cooling tubes 56 of the glazed collector arraypanel 36 between surfaces of outer heating/cooling tubes 56 and innerheating/cooling tubes 58 rises upward to the hot-water storage-tank 38while cooler water descends downward from the hot-water storage-tank 38through the inner heating/cooling tube 58 of the glazed collector arraypanel 36. At the bottom of the solar water-heating-and-cooling system20, cold water descends to the cold water storage tank 46 while warmerwater rise upward therefrom to thereby return again to the thermosyphoncoaxial heating/cooling tubes 52 of the unglazed and glazed collectorarray panels 32, 36. Perforated ends of the inner heating/cooling tubes58 at the top of the cold water storage tank 46 allow descending coolerwater in inner heating/cooling tubes 58, which is warmer than the waterin the cold water storage tank 46, to rise upward between surfaces ofouter and inner tubes 56, 58. In this way, during daytime heat capturedby the glazed collector array panel 36 of the solarwater-heating-and-cooling system 20, and if included the unglazedcollector, array panel 32 of the solar water-heating-and-cooling system20, heats water in the hot-water storage-tank 38 but does not warmcooler water present in the cold water storage tank 46.

The cross-sectional views of FIGS. 3 and 3A-3E show the solarwater-heating-and-cooling system 20 operating to provide cooling throughradiation to the nighttime sky. In the unglazed and glazed collectorarray panels 32, 36 facing the night sky the outer heating/cooling tubes56 radiatively cool through their absorptive/radiative black surfacesand so water between surfaces of the outer and inner tubes 56, 58becomes cooler than water in the inner heating/cooling tubes 58.Consequently, water inside the inner heating/cooling tubes 58 rises andthe water between surfaces of the outer and inner tubes 56, 58 descends.At the top of the solar water-heating-and-cooling system 20, perforatedupper ends of the inner heating/cooling tube 58 located at the bottom ofa lower heated-liquid chamber 74 in the hot-water storage-tank 38 allowrising water, that is cooler than water in the hot-water storage-tank38, descend between the outer and inner tubes 56, 58. In this way hotwater in the hot-water storage-tank 38 is not diluted by cooler waterduring nighttime cooling.

At the very bottom of the solar water-heating-and-cooling system 20depicted in FIGS. 2D-2E and 3D-3E, thermosyphon coaxial cooling tubes ofthe cold radiator array 48 depend beneath the cold water storage tank46. Preferably, the thermosyphon coaxial cooling tubes of the coldradiator array 48 are the same as or similar to the thermosyphon coaxialheating/cooling tubes 52 included in the unglazed collector array panel32. Cool water in the thermosyphon coaxial cooling tubes of the coldradiator array 48 absorbs heat from within the building 26 through thetubes black absorptive surfaces. Hotter water inside the tubes rises upbetween surfaces of outer and inner coaxial tubes of the cold radiatorarray 48 while cooler water descends in the inner coaxial tubes. In thisway the thermosyphon coaxial heating/cooling tubes of the cold radiatorarray 48 absorb heat from the room thereby cooling the room. Duringnighttime, water heated in this way in the thermosyphon coaxial coolingtubes of the cold radiator array 48 eventually rises to the hot-waterstorage-tank 38 atop the roof 24 where it contributes to heating thehot-water storage-tank 38. Therefore the heat collected from the room iseventually reused as hot water, making for a very efficient heatrecovery system.

Mitigating Thermal Shock When Filling The System 20

As best illustrated in FIGS. 4A and 4B and as described comprehensivelyboth in the '968 patent and in the H2231 SIR, upper ends of a number ofparallel thermosyphon coaxial heating/cooling tubes 52 included in theglazed collector array panel 36 extend upward into the bottom of thehot-water storage-tank 38. As depicted in FIGS. 4A and 4B, in accordancewith the present disclosure the hot-water storage-tank 38 includes afloat valve 64 located in a vented upper liquid-supply chamber 66situated high in the hot-water storage-tank 38. The upper liquid-supplychamber 66 provides a source of liquid from which a pipe 68 conveys agravity flow of liquid from the bottom of the upper liquid-supplychamber 66 to the intermediate manifold 34 not illustrated in FIG. 4A or4B. A vent tube 72 extends from the top of the lower heated-liquidchamber 74 situated at the bottom of the hot-water storage-tank 38upward into the upper liquid-supply chamber 66 and extends above aliquid level established therein by operation of the float valve 64.

In a preferred embodiment of the solar water-heating-and-cooling system20, the hot-water storage-tank 38 further includes a cut-off valve 76that connects in series with the float valve 64. The cut-off valve 76operates responsive to sensed water temperature and/or to daylight toautomatically block water from filling the solarwater-heating-and-cooling system 20 when that might possibly damage theglazed collector array panel 36. Activating the cut-off valve 76 whenthe solar water-heating-and-cooling system 20 is likely to be too hotensures that the hot-water storage-tank 38 atop the roof 24 fills withwater only at night when it is cooler, and does not fill during periodsof intense solar radiation. Limiting de-activation of the cut-off valve76 to intervals of low or no solar radiation prevents severe thermalshock to the hot-water storage-tank 38 in the solarwater-heating-and-cooling system 20 and to thermosyphon coaxialheating/cooling tubes 52 of the unglazed and glazed collector arraypanels 32, 36.

Also, as described above, the flow rate of water into the hot-waterstorage-tank 38 may be further regulated by a pressure reducing valve 78that, as depicted in FIGS. 4A and 4B, connects in series with thecut-off valve 76 and the float valve 64. The pressure reducing valve 78is set at a low pressure and flow rate to thereby further reduce thepossibility that the glazed collector array panel 36 will experiencesudden thermal shock. Typically, the pressure reducing valve 78 is setto a pressure that does not exceed 0.3 bar (3 meters water height) and aflow rate that does not exceed 1.0 liter per minute.

Configured as described above, the float valve 64 connects in series viathe cut-off valve 76, the pressure reducing valve 78, and a warmingheat-exchange-coil 82 located in the lower heated-liquid chamber 74 ofthe hot-water storage-tank 38 to a water mains supply 84. Connected inthis way the float valve 64 operates to maintain a constant supply ofwater in the upper liquid-supply chamber 66 of the hot-waterstorage-tank 38 while water pressure is applied to the water mainssupply 84. As is readily apparent to those skilled in the art, waterpresent in the upper liquid-supply chamber 66 flows by gravity via thepipe 68 and the intermediate manifold 34:

-   -   1. to lower ends of thermosyphon coaxial heating/cooling tubes        52 of the glazed collector array panel 36; and    -   2. if the solar water-heating-and-cooling system 20 includes a        unglazed collector array panel 32, to upper ends of thermosyphon        coaxial heating/cooling tubes 52 included therein.        During normal operation of the solar water-heating-and-cooling        system 20 illustrated in FIG. 4A, while the water mains supply        84 supplies water to the solar water-heating-and-cooling system        20 the glazed collector array panel 36 receives water by gravity        flow from the upper liquid-supply chamber 66 via the pipe 68 and        the intermediate manifold 34 thereby ensuring that water flows        upward through the thermosyphon coaxial heating/cooling tubes 52        before filling the lower heated-liquid chamber 74 to thereby        submerge the warming heat-exchange-coil 82. Consequently, water        flowing first into the upper liquid-supply chamber 66 of the        hot-water storage-tank 38 and then via the intermediate manifold        34 into the thermosyphon coaxial heating/cooling tubes 52 of the        glazed collector array panel 36 is preheated by first passing        through the warming heat-exchange-coil 82.

During an extended water mains supply disruption that happens to occuron a sunny day, as described in greater detail above the hot-waterstorage-tank 38 of the solar water-heating-and-cooling system 20 andthermosyphon coaxial heating/cooling tubes 52 being starved for watercan become superheated. If superheating occurs, the hot warmingheat-exchange-coil 82 in the hot-water storage-tank 38 preheats wateradmitted via the water mains supply 84 to the upper liquid-supplychamber 66 which is advantageous for preventing damage due to thermalshock. Furthermore, water flowing through the warming heat-exchange-coil82 from the water mains also cools the hot warming heat-exchange-coil 82and surrounding hot-water storage-tank 38 thereby reducing thermal shockto the warming heat-exchange-coil 82 and surrounding tank when waterultimately refills the lower heated-liquid chamber 74.

Yet another aspect of the hot-water storage-tank 38 depicted in FIG. 4Bmitigates superheating of the hot-water storage-tank 38 of the solarwater-heating-and-cooling system 20 and thermosyphon coaxialheating/cooling tubes 52 in the unglazed and glazed collector arraypanels 32, 36. As depicted in FIG. 4B, if the hot-water storage-tank 38were to boil dry during an extended water mains supply disruption a pairof vents 86, 88 coupled respectively into the top and into the bottom ofthe hot-water storage-tank 38 at both ends thereof permit aircirculation through the hot-water storage-tank 38 and the thermosyphoncoaxial heating/cooling tubes 52 of the unglazed and glazed collectorarray panels 32, 36. Arrows in FIG. 4B indicate air circulation thatoccurs if the hot-water storage-tank 38 boils dry. Air circulatingthrough the hot-water storage-tank 38 and the thermosyphon coaxialheating/cooling tubes 52 of the unglazed and glazed collector arraypanels 32, 36 reduces their maximum temperatures if the hot-waterstorage-tank 38 were to boil dry thereby maintaining the temperaturewithin safe limits and preventing damage due to overheating and during asudden cold fill on a hot day. When during normal operation of the solarwater-heating-and-cooling system 20 the hot-water storage-tank 38 isfull of water:

-   -   1. the water inherently blocks air circulation through the        hot-water storage-tank 38 and the heating/cooling tubes so there        is no undue heat loss;    -   2. the vents 86, 88 operate as conventional water or heating        liquid expansion vents for hot vapor and/or liquid; and    -   3. as indicated in FIGS. 1B, 4A and 4B the upper vents 88 can        provide a gravity fed source of hot water to the building 26.        As depicted in FIGS. 4A and 4B, an outlet of the warming        heat-exchange-coil 82 that connects to the pressure reducing        valve 78 also connects to a hot water outlet 92 for supplying        hot water at the pressure of the water mains supply 84 to        showers or for other use within the building 26.

FIG. 8 illustrates liquid flowing while the solarwater-heating-and-cooling system 20 heats water during daytime:

-   -   1. in thermosyphon coaxial heating/cooling tubes 52 of the        unglazed and glazed collector array panels 32, 36 adjacent to        the intermediate manifold 34; and    -   2. through the intermediate manifold 34.        As indicated by various arrows in FIG. 8, cooler water        descending away from the hot-water storage-tank 38 through the        inner heating/cooling tubes 58 of the thermosyphon coaxial        heating/cooling tubes 52 included in the glazed collector array        panel 36 exits:    -   1. through perforations that pierce the inner heating/cooling        tubes 58 adjacent to the intermediate manifold 34 to flow upward        toward the hot-water storage-tank 38 between outer and inner        tubes 56, 58 of each thermosyphon coaxial heating/cooling tube        52 of the glazed collector array panel 36; and    -   2. through the open end of the inner heating/cooling tubes 58        into the intermediate manifold 34 to flow therefrom either:        -   a. upward toward the hot-water storage-tank 38 between outer            and inner tubes 56, 58 of thermosyphon coaxial            heating/cooling tubes 52 included in the glazed collector            array panel 36; or        -   b. across the intermediate manifold 34 to enter one of the            inner heating/cooling tubes 58 included in the thermosyphon            coaxial heating/cooling tubes 52 of the unglazed collector            array panel 32.            Analogously, warmer water rising toward the hot-water            storage-tank 38 between outer and inner tubes 56, 58 of            thermosyphon coaxial heating/cooling tubes 52 included in            the unglazed collector array panel 32 enters:    -   1. the inner heating/cooling tube 58 of the thermosyphon coaxial        heating/cooling tube 52 through perforations that pierce the        inner heating/cooling tubes 58 adjacent to the intermediate        manifold 34 to flow downward away from, the intermediate        manifold 34 through the inner heating/cooling tube 58; and    -   2. the intermediate manifold 34 through the open end of the        thermosyphon coaxial heating/cooling tube 52 to flow either:        -   a. downward back into the inner heating/cooling tube 58 of            thermosyphon coaxial heating/cooling tubes 52 included in            the unglazed collector array panel 32 and away from the            intermediate manifold 34; or        -   b. across the intermediate manifold 34 to enter one of the            thermosyphon coaxial heating/cooling tubes 52 included in            the glazed collector array panel 36 to flow upward toward            the hot-water storage-tank 38 between outer and inner tubes            56, 58 thereof.

Reversing the flows described above for FIG. 8, FIG. 9 illustratesliquid flowing while the solar water-heating-and-cooling system 20 coolswater during nighttime:

-   -   1. in thermosyphon coaxial heating/cooling tubes 52 of the        unglazed and glazed collector array panels 32, 36 adjacent to        the intermediate manifold 34; and    -   2. through the intermediate manifold 34.        As indicated by various arrows in FIG. 9, cooler water        descending away from the hot-water storage-tank 38 between outer        and inner tubes 56, 58 of each thermosyphon coaxial        heating/cooling tube 52 of the glazed collector array panel 36        enters:    -   1. the inner heating/cooling tube 58 of the thermosyphon coaxial        heating/cooling tube 52 through perforations that pierce the        inner heating/cooling tube 58 adjacent to the intermediate        manifold 34 to then rise toward the hot-water storage-tank 38        through the inner heating/cooling tube 58; or    -   2. the intermediate manifold 34 through the open end of        thermosyphon coaxial, heating/cooling tubes 52 to flow therefrom        either:        -   a. upward toward the hot-water storage-tank 38 through the            inner heating/cooling tube 58 of thermosyphon coaxial            heating/cooling tubes 52 included in the glazed collector            array panel 36; or        -   b. across the intermediate manifold 34 to enter one of the            thermosyphon coaxial heating/cooling tubes 52 included in            the unglazed collector array panel 32 between outer and            inner tubes 56, 58 thereof.            Analogously, warmer arising toward the hot-water            storage-tank 38 through the inner heating/cooling tube 58 of            thermosyphon coaxial heating/cooling tubes 52 included in            the unglazed collector array panel 32 exits:    -   1. through perforations that pierce the inner heating/cooling        tubes 58 adjacent to the intermediate manifold 34 to flow        downward away from the intermediate manifold 34 between outer        and inner tubes 56, 58 of each thermosyphon coaxial        heating/cooling tube 52 of the unglazed collector array panel        32; and    -   2. through the open end of the thermosyphon coaxial        heating/cooling tubes 52 into the intermediate manifold 34 to        flow either:        -   a. downward back into thermosyphon coaxial heating/cooling            tubes 52 included in the unglazed collector array panel 32            and away from the intermediate manifold 34 between outer and            inner tubes 56, 58 of each thermosyphon coaxial            heating/cooling tube 52 of the unglazed collector array            panel 32; or        -   b. across the intermediate manifold 34 to enter one of the            inner heating/cooling tubes 58 of thermosyphon coaxial            heating/cooling tubes 52 included in the glazed collector            array panel 36 to flow upward toward the hot-water            storage-tank 38 through the inner heating/cooling tube 58.

FIG. 10 depicts an alternative embodiment of the intermediate manifold34 depicted in FIG. 8 when heating water during daytime. Those elementsdepicted in FIG. 10 that are common to the intermediate manifold 34illustrated in FIG. 8 carry the same reference numeral distinguished bya prime (“′”) designation. Similar to FIG. 8, FIG. 10 illustrates liquidflowing while the solar water-heating-and-cooling system 20 heats waterduring daytime:

-   -   1. in of the unglazed and glazed collector array panels 32, 36        adjacent to the intermediate manifold 34′; and    -   2. through the intermediate manifold 34′.        The most notable difference between the intermediate manifold        depicted in FIG. 8 and the intermediate manifold 34′ appearing        in FIG. 10 is the inclusion in the intermediate manifold 34′ of        enlarged interconnecting tubes 94 which, differing from        thermosyphon coaxial heating/cooling tubes 52′ appearing in FIG.        10, lack an inner tube. Liquid flow within each individual        interconnecting tube 94 while the solar        water-heating-and-cooling system 20 heats water is essentially        the same as that within the intermediate manifold 34 depicted in        FIG. 8. Though not depicted in any FIG., liquid flow within each        of the interconnecting tube 94 while the solar        water-heating-and-cooling system 20 cools water is essentially        the same as that within the intermediate manifold 34 depicted in        FIG. 9.

The other noteworthy difference between the intermediate manifold 34illustrated in FIG. 8 and the intermediate manifold 34′ illustrated inFIG. 10 is that the intermediate manifold 34′ does not permitintroducing water from the hot-water storage-tank 38 into thethermosyphon coaxial heating/cooling tubes 52′ of the glazed collectorarray panel 36′ via the intermediate manifold 34′. Consequently asdescribed in greater detail below, water that flows from the hot-waterstorage-tank 38 depicted in FIG. 1A into the thermosyphon coaxialheating/cooling tubes 52 of empty unglazed and glazed collector arraypanels 32, 36 via the pipe 68 must bypass the intermediate manifold 34′depicted in FIG. 10 and instead flow into the cold water storage tank46. As is readily apparent, when filling the solarwater-heating-and-cooling system 20, water supplied via the pipe 68′depicted in FIG. 10 to the cold water storage tank 46 first enters thethermosyphon coaxial heating/cooling tubes 52 of the unglazed collectorarray panel 32 from the cold water storage tank 46 before rising to thethermosyphon coaxial heating/cooling tubes 52 of the glazed collectorarray panel 36.

FIG. 11 illustrates an alternative embodiment of the solarwater-heating-and-cooling system 20 of the present disclosure. Thoseelements depicted in FIG. 11 that are common to the solarwater-heating-and-cooling system 20 illustrated in FIGS. 1A, 1B, 2,2A-2E, 3, 3A-3E, and 4A-4B carry the same reference numeraldistinguished by a prime (“′”) designation. As illustrated in FIG. 11,the solar water-heating-and-cooling system 20′ shown there includes oneor more glazed collector array panels 36′ and no unglazed collectorarray panels 32. Furthermore, in addition to intermediate manifolds 34′at lower ends of the glazed collector array panels 36′, each of theglazed collector array panels 36′ includes an upper manifold 102 intowhich thermosyphon coaxial heating/cooling tubes 52 thereof extend. Forthe solar water-heating-and-cooling system 20′ illustrated in FIG. 11,each glazed collector array panels 36′ has:

-   -   1. only a single heated-liquid coaxial tube 104 connecting from        the upper manifold 102 upward to the hot-water storage-tank 38′;        and    -   2. only a single cool-liquid coaxial tube 106 connecting from        the intermediate manifold 34′ downward to the cold water storage        tank 46′.        The individual coaxial tubes 104, 106 carry both hot and cold        water between the glazed collector array panels 36′ and the hot        water and cold water storage tanks 38′, 46′. Both the        intermediate and upper manifolds 34′, 102 share the same design        or can be adapted by closing off the unused outlets of the        multiple connector intermediate manifold 34 depicted in FIGS.        1A, 2, 2C, 3, 3C, and 8-10. The solar water-heating-and-cooling        system 20′ depicted in FIG. 11 may be preferable to that        depicted in FIGS. 1A, 2 and 2A-2E:    -   1. for structural reasons; or    -   2. for aesthetic reasons if it is desirable to:        -   a. hide the hot-water storage-tank 38′ inside a ceiling            attic space or behind a wall 108; and/or        -   b. hide the coaxial tubes 104, 106 from the glazed collector            array panels 36′ to one or more hot water and cold water            storage tanks 38′, 46′; and/or        -   c. limit the number of piping penetrations through the roof            24′ or through walls 108 of the building 26′.            Having fewer or only individual coaxial tubes 104, 106 makes            it easier to hide them by routing them under the roof tiles            22′ or behind walls 108. For the solar            water-heating-and-cooling system 20′ depicted in FIG. 11, to            enable thermosyphon circulation one must ensure that there            is sufficient slope between the glazed collector array            panels 36′ and the hot-water storage-tank 38′ above and the            cold water storage tank 46′ below. Also, as much of the            coaxial tubes 104, 106 as possible, respectively extending            between the intermediate and upper manifolds 34′, 102 and            hot water and cold water storage tanks 38′, 46′, must be            exposed to the sun and nighttime sky to accelerate upward            and downward flows in the coaxial tubes 104, 106. To avoid            heat absorption or radiation which might adversely affect            flows in the upper portion of the cool-liquid coaxial tube            106 outside the building 26′ that is exposed to air, the            length thereof inside the house building 26′ that connects            to the cold water storage tank 46′ must be thermally            insulated.

In addition to filling the glazed collector array panel 36′ with waterflowing via the pipe 68 from the hot-water storage-tank 38 through theintermediate manifold 34′ to the base of the glazed collector arraypanel 36′ as depicted in FIGS. 1A, and 11, those FIGs further indicateanother path by which water from the hot-water storage-tank 38′ mayultimately fill the glazed collector array panel 36′. Similar to FIG.1A, FIG. 11 depicts this alternative path by a dashed line downwardextension of the pipe 68′ that bypasses the intermediate manifold 34′ toenter the top of the cold water storage tank 46′. For a solarwater-heating-and-cooling system 20′ having this alternative path forfilling the glazed collector array panel 36′, after the solarwater-heating-and-cooling system 20 is full of water the pipe 68′advantageously permits any air trapped in the cold water storage tank46′ to escape by bubbling upward inside the pipe 68′ to the upperliquid-supply chamber 66′.

FIG. 12 illustrates the upper manifold 102 of the glazed collector arraypanel 36′ depicted in FIG. 11, and if inverted illustrates theintermediate manifold 34′. Although connections of single coaxial tubes104, 106 respectively to the intermediate and upper manifolds 34′, 102constrain upwards and downwards flows in comparison with the multipleconnector intermediate manifold 34 depicted in FIGS. 8-10, the flows ofhotter and cooler water remain separated inside both of the coaxialtubes 104, 106. Consequently, there is no mixing of upward flowinghotter water and downward flowing cooler water.

The advantage of the upper manifold 102 depicted in FIG. 12 over otherthermosyphon collector panels with single one way manifolds like thatdisclosed in the '578 patent is that thermosyphon efficiency increasesbecause lateral flow extends only half way across the width of thecollector array panel compared to known solar water heating systems suchas that disclosed in the '578 patent where the horizontal flow extendsthe full width of the collector array panel. Having a shorter horizontalflow distance across a manifold increases thermosyphon efficiency.Furthermore, the coaxial tubes 104, 106 connecting glazed collectorarray panels 36′ to the hot water and cold water storage tanks 38′, 46′increase thermal efficiency due to preheating and precooling occurringbecause the outer tube surrounds the inner tube of the coaxial tubes104, 106.

Moreover, if installation of the solar water-heating-and-cooling system20′ hides the hot-water storage-tank 38′ only one penetration hole needbe made through the roof tiles 22′ or concrete of a wall 108. Incomparison, hiding the tank disclosed in the '578 patent behind a wallor inside a ceiling attic space requires making two (2) penetrationholes, i.e. one for the hot water flow and one for the cooler waterreturn flow. Requiring only a single penetration speeds up andsimplifies installation of a solar water-heating-and-cooling system 20′,reduces labor costs, and reduces the possibility of leakage.

FIG. 13 depicts the simplest alternative embodiment of the solarwater-heating-and-cooling system 20 of the present disclosure that onlyheats water. Those elements depicted in FIG. 13 that are common to thesolar water-heating-and-cooling system 20 illustrated in FIGS. 1A, 1B,2, 2A-2E, 3, 3A-3E, 4A-4B, and 11 carry the same reference numeraldistinguished by a double prime (“″”) designation. The solarwater-heating-and-cooling system 20″ includes only a single glazedcollector array panel 36″ that a single heated-liquid coaxial tube 104″connects to the hot-water storage-tank 38″. Similar to the solarwater-heating-and-cooling system 20 depicted in FIG. 11, the hot-waterstorage-tank 38″ of the solar water-heating-and-cooling system 20″depicted in FIG. 13 can be hidden inside the ceiling attic space.Installed in this way, only the glazed collector array panel 36″ isvisible from outside the building 26″. The glazed collector array panel36″ depicted in FIG. 13 does not need and therefore lacks a intermediatemanifold 34. For the solar water-heating-and-cooling system 20″ depictedin FIG. 13, lacking an intermediate manifold 34, rather than the pipe 68supplying cold water to the intermediate manifold 34, cold water flowingby gravity from the upper liquid-supply chamber 66″ of the hot-waterstorage-tank 38″ enters the lower heated-liquid chamber 74″ of thehot-water storage-tank 38″ at the bottom thereof with the pipe 68″connecting to one of the lower vents 86″.

Because the glazed collector array panel 36″ depicted in FIG. 13 lacksthe intermediate manifold 34, it may instead advantageously include aset of opening tube holders 122, depicted in FIGS. 14 and 15, thatpreferably are equal in number to the number of thermosyphon coaxialheating/cooling tubes 52″. Each tube holder 122 mates individually witha lower end 124 of a thermosyphon coaxial heating/cooling tube 52″. Asdepicted in FIGS. 14 and 15, each tube holder 122 includes:

-   -   1. a flat plate 126 having a hole 128 formed therethrough; and    -   2. a curved section 132.        As best illustrated in FIG. 15, a hinge 136 secures one end of        each flat plate 126 to a frame 138 of the glazed collector array        panel 36″. When securing a thermosyphon coaxial heating/cooling        tube 52″ to the frame 138, the flat plate 126 becomes oriented        essentially perpendicular to the frame 138. A hinge 142 located        at the end of the flat plate 126 that is furthest from the hinge        136 and the frame 138 secures one end of the curved section 132        to the flat plate 126. The end of the curved section 132        furthest from the flat plate 126 and hinge 142 has a lip 144        formed thereat for securing that end of the curved section 132        to the frame 138.

When securing a thermosyphon coaxial heating/cooling tube 52″ to theframe 138, as depicted in FIG. 15 a slot 146 at an end of the frame 138furthest from the hinge 136 receives the lip 144 of the tube holder 122.When the slot 146 receives the lip 144, the tube holder 122 orients thecurved section 132 so it presents a concave, essentially circularcurved-shape toward the hinge 136. A threaded end of a bolt 152 thatpasses through a hole 154 in the lip 144 and through a matching hole 156in the frame 138 mates with threads of a nut 158 thereby securing thelip 144 to the frame 138 when the lip 144 is located in the slot 146. Indisposing the lip 144 in the slot 146 when mating the tube holder 122with lower end 124 of the thermosyphon coaxial heating/cooling tube 52″,the hole 128 in the flat plate 126 receives a cup 162 made from PVCmaterial. Also, a silicon rubber O-ring 164 received into the cup 162fits between the cup 162 and the lower end 124 of the thermosyphoncoaxial heating/cooling tube 52″. As indicated by the dashed linedepiction of the curved section 132 in FIG. 15, compliance of the tubeholder 122 permits accommodating expansion and contraction of thethermosyphon coaxial heating/cooling tube 52″ that occurs due tochanging temperature such as diurnal heating and cooling.

FIG. 16 depicts yet another alternative embodiment solarwater-heating-and-cooling system 20. Those elements depicted in FIG. 16that are common to the solar water-heating-and-cooling system 20 and 20′respectively illustrated in FIGS. 1A, 1B, 2, 2A-2E, 3, 3A-3E, 4A-4B and11 carry the same reference numeral distinguished by a triple prime(“′″”) designation. The solar water-heating-and-cooling system 20′″depicted in FIG. 16 differs from those other embodiments by including apair of glazed collector array panels 36′″ each of which rests on adifferent roof surface 168, the roof surfaces 168 abutting each other atthe ridge 42′″ immediately beneath the hot-water storage-tank 38′″. Asillustrated in FIG. 16, intermediate manifolds 34′″ of the solarwater-heating-and-cooling system 20′″ respectively connect in parallelto opposite ends of the cold water storage tank 46′″.

In equatorial regions of the earth and in the tropics, some part ofnon-planar roofs 24′″ having an inclination to the horizontal of morethan 25 degrees (25°) to the horizontal face away from the sun or areeven in shade at different times of the day or at different seasons ofthe year. For roof surfaces 168 that respectively face east and west,the west facing roof surface 168 is in shade or faces away from the sunat sunrise and through some part of the morning. Correspondingly, theeast facing roof surface 168 faces away from the sun at sunset andthrough the later part of the afternoon and evening. At the equator, forroof surfaces 168 that respectively face north and south, the northfacing roof surface 168 faces away from the sun from October untilFebruary, and the south facing roof surface 168 faces away from the sunfrom April to August.

Having glazed collector array panel 36′″ located on roof surfaces 168that face away from the sun increases the cooling capacity of the solarwater-heating-and-cooling system 20′″. For instance, during lateafternoon or evening the glazed collector array panel 36′″ located onthe roof surface 168 that faces east begins radiating heat out to thesky during daytime thereby beginning to cool water a few hours soonerthan the glazed collector array panel 36′″ located on the roof surface168 that faces west. Correspondingly, the roof surface 168 that faceswest continues radiating heat out to the sky thereby continuing to coolwater a few hours later during daytime than the glazed collector arraypanel 36′″ located above the roof surface 168 that faces east.Furthermore, a steeper slope for roof surfaces 168 increases thedifference in solar exposure between two (2) glazed collector arraypanel 36′″ respectively located thereon.

Considering the solar water-heating-and-cooling system 20′″ illustratedin FIG. 16 for clear sky conditions, it is evident that hot water in theglazed collector array panel 36′″ that is exposed to the sun rises intothe hot-water storage-tank 38′″, and hot water does not descend into thecold water storage tank 46′″. Correspondingly, cooled water in theglazed collector array panel 36′″ that is not exposed to the sun doesnot rise into the hot-water storage-tank 38′″, but rather descends intothe cold water storage tank 46′″. Due to perforations in upper and lowerends of inner heating/cooling tubes 58′″ of the glazed collector arraypanels 36′″, heated and cooled water respectively in each of the glazedcollector array panels 36′″ flows independently of the flow in the otherglazed collector array panel 36′″. Consequently, the solarwater-heating-and-cooling system 20′″ illustrated in FIG. 16 avoids anymixing of respective flows of hot and cold water in the pair of glazedcollector array panels 36′″.

In this way, a pair of glazed collector array panel 36′″ arranged asdepicted in FIG. 16 supplies hot water to the hot-water storage-tank 38″for more time each day in comparison with a solarwater-heating-and-cooling system 20 having only a single glazedcollector array panel 36. Thus, the arrangement of the glazed collectorarray panel 36′″ illustrated in FIG. 16 provides the solarwater-heating-and-cooling system 20′″ with better heating and coolingefficiencies in comparison with a solar water-heating-and-cooling system20 having all its glazed collector array panels 36 facing, in the samedirection.

North of the Tropic of Cancer, a glazed collector array panel 36′″ thatfaces directly north receives no direct solar radiation, but doesreceive indirect solar radiation reflected from clouds and the sky. Thisindirect solar radiation might be only a third or less of that receivedby a south facing glazed collector array panel 36′″. Furthermore,depending on weather conditions the directly north facing glazedcollector array panel 36′″ radiates more or less heat. On overcastcloudy days incoming solar radiation is diffuse, perhaps being one-thirdor less of that on, a sunny day. However, such a weather conditionspreads solar radiation more evenly throughout the sky. Consequently, itis readily apparent that whether a solar collector facing away from thesun receives solar radiation or radiates heat depends on variousconditions, e.g. orientation of the ridge 42′″, slope of roof surfaces168, sky condition such as clear blue sky or overcast, latitude at whichthe solar water-heating-and-cooling system 20′″ is installed, time ofyear and time of day, etc.

Values of heat absorption or heat loss for a particular location andorientation for the solar water-heating-and-cooling system 20′″ and timecan be assessed using a computer program that incorporates the sun'spath for the installation location of the solarwater-heating-and-cooling system 20′″. Recognizing that the sun's pathacross the sky is a curve and not a straight line, between the Tropicsof Cancer and Capricorn, which constitutes a large fraction of theearth's surface, most installations of the solarwater-heating-and-cooling system 20′″ generally exhibit both cooling andheating during daytime throughout the year regardless of the orientationof the roof surfaces 168. So in that region of the world additional two(2) or more glazed collector array panel 36′″ located on different roofsurfaces 168 are generally advantageous. Outside of the Tropics, a pairof east and west facing glazed collector array panels 36′″ benefit fromincreased heating and cooling, while a pair of glazed collector arraypanel 36′″ respectively facing south and north provides heating from oneglazed collector array panel 36′″ and cooling from the other glazedcollector array panel 36′″ which during daytime generally behaves morelike radiator. Accordingly, in most instances multiple glazed collectorarray panels 36′″ on differently oriented roof surfaces 168 proveadvantageous for increasing the heating and cooling capacities of thesystem regardless where the system is located geographically.

INDUSTRIAL APPLICABILITY

One or more drains 174 located in the base of the cold water storagetank 46 and illustrated in FIGS. 2D, 3D and 16 permit:

-   -   1. drawing a gravity flow of cold water from the cold water        storage tank 46, for household or other use;    -   2. pumping cold water around a closed circuit within the        building 26 to radiators other than the cold radiator array 48        or for other similar uses thereby effectively using the solar        water-heating-and-cooling system 20 as a cooling tower; and    -   3. draining substantially all water from the solar        water-heating-and-cooling system 20 except for that in the cold        radiator array 48, for example when the solar        water-heating-and-cooling system 20 requires maintenance.        Note that draining water from the cold radiator array 48        requires removing screw caps 176, illustrated by an enlargement        within FIG. 16, from the lower end of each thermosyphon coaxial        cooling tube included in the cold radiator array 48.

Analogous to the cold water storage tank 46 providing a low pressuresource of cold water for various uses as described above, a low pressuresupply of hot water may be drawn from the hot-water storage-tank 38 viathe upper vents 88 as described above, or via the lower vents 86.

Similar to the warming heat-exchange-coil 82 located in the lowerheated-liquid chamber 74 of the hot-water storage-tank 38, the coldwater storage tank 46 may advantageously also have an equivalent coolingheat-exchange-coil 172 located therein. The cooling heat-exchange-coil172 equips the solar water-heating-and-cooling system 20 for providing asupply of cold liquid, separate from that present within the solarwater-heating-and-cooling system 20, that may be used for variouspurposes depending upon the particular type of liquid supplied thereto.For example, if potable water, such as that supplied via the water mainssupply 84 to the hot-water storage-tank 38, is also supplied to thecooling heat-exchange-coil 172, then the cooling heat-exchange-coil 172can supply cold drinking water to the building 26. Alternatively,similar to drains 174 included in the base of the cold water storagetank 46, cold water may be pumped around a closed circuit that includesthe cooling heat-exchange-coil 172 to radiators other than the coldradiator array 48 or for other similar uses thereby again effectivelyusing the solar water-heating-and-cooling system 20 as a cooling tower.Similarly, for industrial applications that require cooling hot fluidssuch as hot refrigerant from an air conditioning compressor or heatexchanger, the hot fluid can be cooled by passing it through the coolingheat-exchange-coil 172 in the cold water storage tank 46.

Parts of the solar water-heating-and-cooling system 20 that are outsidea building 26 or other type of building, such as the hot-waterstorage-tank 38, unglazed and glazed collector array panels 32, 36respectively and the intermediate and upper manifolds 34, 102respectively, can be incorporated into various components of thebuilding such as its roof 24 or walls 108. The unglazed and/or glazedcollector array panels 32, 36 can even be incorporated into windowsand/or skylights because if they omit the highly reflective surface 62some light passes through the thermosyphon coaxial heating/cooling tubes52. If the solar water-heating-and-cooling system 20 is to heat abuilding, the hot-water storage-tank 38 can be incorporated into thebuilding's internal structure such as a ceiling, floor or internal wallwhere it can radiate heat directly into a room. Similarly, if the solarwater-heating-and-cooling system 20 is to cool a building, the colawater storage tank 46 and the cold radiator array 48 can also beincorporated into the building's internal structure such as ceilings,ceiling cornices, internal walls and partitions, load bearing structure,columns, floors and floor skirting boards, etc., where such componentsof the solar water-heating-and-cooling system 20 can absorb heatdirectly from the room. Integrating components of the solarwater-heating-and-cooling system 20 directly into a building as outlinedabove will both reduce building cost and improve aesthetics.

For office buildings anywhere in the world, having some unglazed and/orglazed collector array panels 32, 36 facing away from the sun during thedaytime such as described for the solar water-heating-and-cooling system20′″ depicted in FIG. 16 eliminates from roofs of building noisy,visually obtrusive, vibration and maintenance prone air conditioningcooling towers. If only hot air conditioning refrigerant or other hotfluids need be cooled only some of the time, the cold water storage tank46 may be located on the roof 24 or exterior wall 108 of the building,and have opening or adjustable movable insulated covers over the coldwater storage tank 46, not illustrated in any of the FIGs, both to aninterior space within the building and to the outside. Whenever hotrefrigerant flows through the cooling heat-exchange-coil 172, thesecovers when closed to the interior of the building prevent hot fluid inthe cooling heat-exchange-coil 172 from radiating heat back into thebuilding that is to be cooled. On moderately warm days, the cold waterstorage tank 46 connected to unglazed and/or glazed collector arraypanels 32, 36 facing away from the sun functions as a passive radiativecooler with insulated covers open into the building, and closed to theoutside. On very hot days when the air conditioning system of thebuilding is operating and the hot refrigerant from a compressor flowsthrough the cooling heat-exchange-coil 172 with the solarwater-heating-and-cooling system 20 functioning as a cooling tower, thenthe insulated covers to cold water storage tank 46 open to the outsideand close to the interior of the building. Replacing air conditioningcooling towers with the unglazed and/or glazed collector array panels32, 36 will be cost effective particularly if they are incorporated intothe building's roof 24. Because the unglazed and/or glazed collectorarray panels 32, 36 are relatively maintenance free, silent, passivewith no moving parts and require no electrical energy, they constitutean elegant replacement for air conditioning water cooling towersworldwide.

Deciding whether to incur additional expense to increase the heatingcapacity by installing the type of solar water-heating-and-coolingsystem 20′″ depicted in FIG. 16 depends on various considerationsmentioned above. In general, for northern hemisphere locationsinstalling an extra solar collector on a south facing roof surface isadvantageous. For east-west facing roof surfaces 168, having multipleglazed collector array panel 36′″ facing in opposite directions, doublesheating capacity of the solar water-heating-and-cooling system 20′″. Ifthe solar water-heating-and-cooling system 20′″ is to producesignificant cooling, then directing one glazed collector array panel36′″ away from the sun is particularly advantageous.

Exploiting evaporative cooling of water from the unglazed and/or glazedcollector array panels 32, 36, the solar water-heating-and-coolingsystem 20 is able to capture and store extra cooling effect of passingrain showers. Lacking the solar water-heating-and-cooling system 20, thecooling effect of rain is transient, lasting for only a short intervaluntil the sun comes out. Furthermore, the effect of a rain shower islimited to a building's roof 24, and therefore does not effectively coolthe building's interior. The solar water-heating-and-cooling system 20permits capturing a rain shower's full cooling effect, and storing thecooling effect in the cold water storage tank 46. Furthermore, if thebuilding captures rainwater or if mains water supply is plentiful suchas the Tropics, on hot afternoons water can be sprayed onto the unglazedand/or glazed collector array panels 32, 36 facing away from the sun toincrease cooling. As explained above, water applied to unglazed and/orglazed collector array panels 32, 36 facing away from the sun does notcool hot water stored in the hot-water storage-tank 38.

A cost benefit analysis for installing currently available solarcollectors that only absorb heat and do not cool is necessarily limitedsolely to assessing whether the heat gained is worth the expense. Asexplained below, the solar water-heating-and-cooling system 20, 20′ and20′″ disclosed herein effectively changes the cost benefit analysis byhalving the cost when both heating and cooling are required. A decisionwhether to install additional glazed collector array panel 36′″ onanother roof surface 168 or the same slope requires evaluating whetherextra heating or cooling is required, and after a detailed analysis suchas that outlined above.

The efficiency of the solar water-heating-and-cooling system 20, 20′,20″ and 20′″ lies in its being a naturally reversible passive solarcollector or radiative cooler depending on conditions and time of dayand season of the year. The solar water-heating-and-cooling system 20,20′, 20″ and 20′″ wastes no incoming heat; and the hot-waterstorage-tank 38, 38′, 38″ or 38′″ stores all incoming heat safely.Similarly, the solar water-heating-and-cooling system 20, 20′ and 20′″wastes no cooling absorbing all available chilling and stores it in thecold water storage tank 46, 46′ or 46′″. Thus. in terms of costefficiency, the solar water-heating-and-cooling system 20, 20′, 20″ and20′″ significantly advances solar water-heating technology by improvingreliability, and providing glazed collector array panels 36, 36′ and36′″ that double as a passive and natural heater and cooler without anypumps, manual switches or timers etc. thereby reducing costs andmaintenance.

For the preceding reasons, the solar water-heating-and-cooling system20, 20′, 20″ and 20′″ are advantageous both for residential and forcommercial applications, particularly for geographic locations betweenthe Tropics of Cancer and Capricorn when both heating and cooling aredesired. Compared with currently available solar water-heating systemsand water-cooling systems, the solar water-heating-and-cooling system20, 20′ and 20′″ effectively halve the initial cost of solar collectorsand installation, and roof space required by effectively using both orall roof surfaces 168. In this way a building owner may maximizecollection of heat energy incident upon and cooling capability of everyroof surface 168 on a building, a significant consideration if roofspace is at a premium.

A solar water-heating-and-cooling system 20 in accordance with thepresent disclosure may omit the upper liquid-supply chamber 66 and thefloat valve 64 replacing them with an automatic control valve, notillustrated in any of the FIGs, that controls the liquid level withinthe lower heated-liquid chamber 74. When substituting an automaticcontrol valve for the upper liquid-supply chamber 66 and the float valve64, the automatic control valve is coupled to the water mains supply 84and supplies water to the lower heated-liquid chamber 74. The automaticcontrol valve responds to liquid pressure in the lower heated-liquidchamber 74 for maintaining a proper amount of liquid in the unglazed andglazed collector array panels 32, 36 and lower heated-liquid chamber 74of the solar water-heating-and-cooling system 20. Various suppliersoffer automatic control valves which may be used for replacing the upperliquid-supply chamber 66 and the float valve 64. Yi Thoong of Chinamarkets an automatic control valve suitable for controlling fluid levelin the lower heated-liquid chamber 74.

Although the present invention has been described in terms of thepresently preferred embodiment, it is to be understood that suchdisclosure is purely illustrative and is not to be interpreted aslimiting. Consequently, without departing from the spirit and scope ofthe disclosure, various alterations, modifications, and/or alternativeapplications of the disclosure will, no doubt, be suggested to thoseskilled in the art after having read the preceding disclosure.Accordingly, it is intended that the following claims be interpreted asencompassing all alterations, modifications, or alternative applicationsas fall within the true spirit and scope of the disclosure.

1. A solar heating system (20) comprising: a. at least one collectorarray panel (32, 36) adapted for being located on a sloping roof (24) ofa building (26), the collector array panel (32, 36) including at leastone thermosyphon heating tube (52); b. a liquid source adapted forsupplying liquid to said heating tube (52) of said collector array panel(32, 36); and c. a cut-off valve (76) coupled both to: i. a mains supply(84) for receiving liquid therefrom; and ii. said liquid source forautomatically blocking liquid received by said cut-off valve (76) fromsaid mains supply (84) from filling said heating tube (52) of saidcollector array panel (32, 36) whenever such filling could damage saidcollector array panel (32, 36).
 2. The solar heating system (20) ofclaim 1 wherein said liquid source includes a chamber (66) that uponreceiving liquid via said cut-off valve (76) supplies liquid by gravityto said heating tube (52) of said collector array panel (32, 36).
 3. Thesolar heating system (20) of claim 1 wherein said cut-off valve (76)operates automatically responsive to light for blocking filling of saidheating tube (52) of said collector array panel (32, 36) whenever suchfilling could damage said collector array panel (32, 36).
 4. The solarheating system (20) of claim 1 wherein said cut-off valve (76) operatesautomatically responsive to temperature for blocking filling of saidheating tube (52) of said collector array panel (32, 36) whenever suchfilling could damage said collector array panel (32, 36).
 5. The solarheating system (20) of claim 1 further comprising a pressure reducingvalve (78): a. coupled in series with said cut-off valve (76) betweensaid mains supply (84) and said liquid source; and b. set at a lowpressure and flow rate, for further reducing a possibility that fillingsaid heating tube (52) of said collector array panel (32, 36) coulddamage said collector array panel (32, 36).
 6. (canceled)
 7. (canceled)8. The solar heating system (20) claim 1 further comprising: d: aheated-liquid chamber (74) that is coupled to an upper end of said atleast one heating tube (52) of said collector array panel (32, 36) forreceiving hot liquid warmed within said collector array panel (32, 36);and e: a warming heat-exchange-coil (82) that is located within saidheated-liquid chamber (74), and that is coupled in series with saidcut-off valve (76) between said mains supply (84) and said liquid sourcefor heating liquid received from said mains supply (84).
 9. The solarheating system (20) of claim 1 wherein said liquid source includes anautomatic control valve that is coupled in series with said cut-offvalve (76) between said mains supply (84) and a heated-liquid chamber(74) included in the solar heating system (20), said automatic controlvalve: a. supplying liquid to said heated-liquid chamber (74) from whichliquid flows by gravity to said heating tube (52) of said collectorarray panel (32, 36); and c. responding to liquid pressure in saidheated-liquid chamber (74) for maintaining a proper amount of liquid inthe solar heating system (20).
 10. The solar heating system (20) ofclaim 9 further comprising pressure reducing valve (78): a. coupled inseries with said cut-off valve (76) between said mains supply (84) andsaid liquid source; and b. set at a low pressure and flow rate, forfurther reducing a possibility that filling said heating tube (52) ofsaid collector array panel (32, 36) could damage said collector arraypanel (32, 36).
 11. (canceled)
 12. (canceled)
 13. The solar heatingsystem (20) of claim 9 wherein said heated-liquid chamber (74) iscoupled to an upper end of said at least one heating tube (52) of saidcollector array panel (32, 36) for receiving hot liquid warmed withinsaid collector array panel (32, 36), and further includes a warmingheat-exchange-coil (82) that is located within said heated-liquidchamber (74), and that is coupled in series with said cut-off valve (76)between said mains supply (84) and said liquid source for heating liquidreceived from said mains supply (84).
 14. A solar heating system (20)comprising: a. at least one collector array panel (32, 36) adapted forbeing located on a sloping roof (24) of a building (26), the collectorarray panel (32, 36) including at least one thermosyphon heating tube(52), each heating tube (52) being open at a lower end thereof; b. anintermediate manifold (34) coupled to lower ends of said heating tube(52) of said collector array panel (32, 36) for supplying liquidthereto; c. a liquid source adapted for supplying liquid via saidintermediate manifold (34) to lower ends of said heating tube (52) ofsaid collector array panel (32, 36); and d. a pressure reducing valve(78) being: i. coupled between a mains supply (84) and said liquidsource; and ii. set at a low pressure and flow rate for limiting a rateat which said heating tube (52) of said collector array panel (32, 36)slowly fills with liquid thereby preventing filling of said heating tube(52) from damaging said collector array panel (32, 36).
 15. (canceled)16. (canceled)
 17. The solar heating system (20) of claim 14 whereinsaid liquid source includes a chamber (66) that upon receiving liquidfrom said mains supply (84) via said pressure reducing valve (78)supplies liquid by gravity to said heating tube (52) of said collectorarray panel (32, 36) via said intermediate manifold (34).
 18. The solarheating system (20) of claim 14 further comprising a cut-off valve (76)coupled in series with said pressure reducing valve (78), said cut-offvalve (76) operating automatically responsive to light for blockingfilling of said heating tube (52) of said collector array panel (32, 36)whenever such filling could damage said collector array panel (32, 36).19. The solar heating system (20) of claim 14 further comprising acut-off valve (76) coupled in series with said pressure reducing valve(78), said cut-off valve (76) operating automatically responsive totemperature for blocking filling of said heating tube (52) of saidcollector array panel (32, 36) whenever such filling could damage saidcollector array panel (32, 36).
 20. The solar heating system (20) ofclaim 14 further comprising: d: a heated-liquid chamber (74) that iscoupled to an upper end of said at least one heating tube (52) of saidcollector array panel (32, 36) for receiving hot liquid warmed withinsaid collector array panel (32, 36); and e: a warming heat-exchange-coil(82) that is located within said heated-liquid chamber (74), and that iscoupled in series with said pressure reducing valve (78) between saidmains supply (84) and said liquid source for heating liquid receivedfrom said mains supply (84).
 21. The solar heating system (20) of claim14 wherein said liquid source includes an automatic control valve thatis coupled in series with said pressure reducing valve (78) between saidmains supply (84) and a heated-liquid chamber (74) included in the solarheating system (20), said automatic control valve: a. supplying liquidto said heated-liquid chamber (74) from which liquid flows by gravityvia said intermediate manifold (34) to said heating tube (52) of saidcollector array panel (32, 36); and c. responding to liquid pressure insaid heated-liquid chamber (74) for maintaining a proper amount ofliquid in the solar heating system (20).
 22. (canceled)
 23. (canceled)24. The solar heating system (20) of claim 21 wherein said heated-liquidchamber (74) is coupled to an upper end of said at least one heatingtube (52) of said collector array panel (32, 36) for receiving hotliquid warmed within said collector array panel (32, 36), and furtherincludes a warming heat-exchange-coil (82) that is located within saidheated-liquid chamber (74), said warming heat-exchange-coil (82) beingcoupled in series with said cut-off valve (76) between said mains supply(84) and said liquid source for heating liquid received from said mainssupply (84).
 25. A solar heating-and-cooling system (20) comprising: a.at least one collector array panel (32, 36) adapted for being located ona sloping roof (24) of a building (26), the collector array panel (32,36) including at least one thermosyphon heating/cooling tube (52), eachheating/cooling tube (52) being open both: i. at an upper end of saidcollector array panel (32, 36); and ii. at a lower end thereof; b. aheated-liquid chamber (74) located at a distance above and separatedfrom the upper end of said collector array panel (32, 36) that iscoupled to an upper end of said at least one heating tube (52) of saidcollector array panel (32, 36) for receiving hot liquid warmed withinsaid collector array panel (32, 36); and c. a cold liquid storage tank(46) located at a distance below and separated from the lower end ofsaid collector array panel (32, 36) that is coupled to a lower end ofsaid at least one heating tube (52) of said collector array panel (32,36) for receiving cool liquid chilled within said collector array panel(32, 36).
 26. The solar heating-and-cooling system (20) of claim 25further comprising a cold radiator array (48) that is located beneathand coupled to said cold liquid storage tank (46) for receiving coolliquid therefrom.
 27. The solar heating-and-cooling system (20) of claim25 further comprising a warming heat-exchange-coil (82) that is locatedwithin said heated-liquid chamber (74).
 28. The solarheating-and-cooling system (20) of claim 25 further comprising a coolingheat-exchange-coil (172) that is located within said cold liquid storagetank (46).
 29. The solar heating-and-cooling system (20) of claim 25wherein: d. said collector array panel (32, 36) includes an uppermanifold (102) located at the upper end of said collector array panel(32, 36) that exchange liquid with said heating/cooling tube (52)thereof; and e. via said upper manifold (102), at least oneheated-liquid coaxial tube (104) conducts liquid between saidheating/cooling tube (52) of said collector array panel (32, 36) andsaid heated-liquid chamber (74).
 30. The solar heating-and-coolingsystem (20) of claim 25 wherein: d. said collector array panel (32, 36)includes a manifold (34) located at the lower end of said collectorarray panel (32, 36) that exchanges liquid with said heating/coolingtube (52) thereof; and e. via said manifold (34), at least onecool-liquid coaxial tube (106) conducts liquid between saidheating/cooling tube (52) of said collector array panel (32, 36) andsaid cold liquid storage tank (46).
 31. A radiative cooling system (20)comprising: a. at least one collector array panel (32, 36) adapted forbeing located on a sloping roof (24) of a building (26), the collectorarray panel (32, 36) including at least one thermosyphon cooling tube(52), each cooling tube (52) being open at a lower end of said collectorarray panel (32, 36); and b. a cold liquid storage tank (46) located ata distance below and separated from the lower end of said collectorarray panel (32, 36) that is coupled to a lower end of said at least oneheating tube (52) of said collector array panel (32, 36) for receivingcool liquid chilled within said collector array panel (32, 36).
 32. Theradiative cooling system (20) of claim 31 further comprising a coldradiator array (48) that is located beneath and coupled to said coldliquid storage tank (46) for receiving cool liquid therefrom.
 33. Theradiative cooling system (20) of claim 31 further comprising a coolingheat-exchange-coil (172) that is located within said cold liquid storagetank (46).
 34. The radiative cooling system (20) of claim 31 wherein: c.said collector array panel (32, 36) includes a manifold (34) located atthe lower end of said collector array panel (32, 36) that exchangesliquid with said cooling tube (52) thereof; and d. via said manifold(34), at least one cool-liquid coaxial tube (106) conducts liquidbetween said cooling tube (52) of said collector array panel (32, 36)and said cold liquid storage tank (46).
 35. A solar heating system (20)comprising: a. at least one collector array panel (32, 36) adapted forbeing located on a sloping roof (24) of a building (26), the collectorarray panel (32, 36) including: i. at least one thermosyphon heatingtube (52), each of the heating tube (52) being open at an upper end ofsaid collector array panel (32, 36); and ii. an upper manifold (102)located at the upper end of said collector array panel (32, 36) thatexchanges liquid with said heating tube (52) thereof; b. a heated-liquidchamber (74) located at a distance above and separated from the upperend of said collector array panel (32, 36) for receiving hot liquidwarmed within said collector array panel (32, 36); and c. via said uppermanifold (102), at least one heated-liquid coaxial tube (104) conductsliquid between said heating tube (52) of said collector array panel (32,36) and said heated-liquid chamber (74).
 36. The solar heating system(20) of claim 2 further comprising: d: a heated-liquid chamber (74) thatis coupled to an upper end of said at least one heating tube (52) ofsaid collector array panel (32, 36) for receiving hot liquid warmedwithin said collector array panel (32, 36); and e: a warmingheat-exchange-coil (82) that is located within said heated-liquidchamber (74), and that is coupled in series with said cut-off valve (76)between said mains supply (84) and said liquid source for heating liquidreceived from said mains supply (84).
 37. The solar heating system (20)of claim 3 further comprising: d: a heated-liquid chamber (74) that iscoupled to an upper end of said at least one heating tube (52) of saidcollector array panel (32, 36) for receiving hot liquid warmed withinsaid collector array panel (32, 36); and e: a warming heat-exchange-coil(82) that is located within said heated-liquid chamber (74), and that iscoupled in series with said cut-off valve (76) between said mains supply(84) and said liquid source for heating liquid received from said mainssupply (84).
 38. The solar heating system (20) of claim 4 furthercomprising: d: a heated-liquid chamber (74) that is coupled to an upperend of said at least one heating tube (52) of said collector array panel(32, 36) for receiving hot liquid warmed within said collector arraypanel (32, 36); and e: a warming heat-exchange-coil (82) that is locatedwithin said heated-liquid chamber (74), and that is coupled in serieswith said cut-off valve (76) between said mains supply (84) and saidliquid source for heating liquid received from said mains supply (84).39. The solar heating system (20) of claim 5 further comprising: d: aheated-liquid chamber (74) that is coupled to an upper end of said atleast one heating tube (52) of said collector array panel (32, 36) forreceiving hot liquid warmed within said collector array panel (32, 36);and e: a warming heat-exchange-coil (82) that is located within saidheated-liquid chamber (74), and that is coupled in series with saidcut-off valve (76) between said mains supply (84) and said liquid sourcefor heating liquid received from said mains supply (84).
 40. The solarheating system (20) of claim 15 further comprising: d: a heated-liquidchamber (74) that is coupled to an upper end of said at least oneheating tube (52) of said collector array panel (32, 36) for receivinghot liquid warmed within said collector array panel (32, 36); and e: awarming heat-exchange-coil (82) that is located within saidheated-liquid chamber (74), and that is coupled in series with saidpressure reducing valve (78) between said mains supply (84) and saidliquid source for heating liquid received from said mains supply (84).41. The solar heating system (20) of claim 16 further comprising: d: aheated-liquid chamber (74) that is coupled to an upper end of said atleast one heating tube (52) of said collector array panel (32, 36) forreceiving hot liquid warmed within said collector array panel (32, 36);and e: a warming heat-exchange-coil (82) that is located within saidheated-liquid chamber (74), and that is coupled in series with saidpressure reducing valve (78) between said mains supply (84) and saidliquid source for heating liquid received from said mains supply (84).42. The solar heating system (20) of claim 17 further comprising: d: aheated-liquid chamber (74) that is coupled to an upper end of said atleast one heating tube (52) of said collector array panel (32, 36) forreceiving hot liquid warmed within said collector array panel (32, 36);and e: a warming heat-exchange-coil (82) that is located within saidheated-liquid chamber (74), and that is coupled in series with saidpressure reducing valve (78) between said mains supply (84) and saidliquid source for heating liquid received from said mains supply (84).43. The solar heating system (20) of claim 18 further comprising: d: aheated-liquid chamber (74) that is coupled to an upper end of said atleast one heating tube (52) of said collector array panel (32, 36) forreceiving hot liquid warmed within said collector array panel (32, 36);and e: a warming heat-exchange-coil (82) that is located within saidheated-liquid chamber (74), and that is coupled in series with saidpressure reducing valve (78) between said mains supply (84) and saidliquid source for heating liquid received from said mains supply (84).44. The solar heating system (20) of claim 19 further comprising: d: aheated-liquid chamber (74) that is coupled to an upper end of said atleast one heating tube (52) of said collector array panel (32, 36) forreceiving hot liquid warmed within said collector array panel (32, 36);and e: a warming heat-exchange-coil (82) that is located within saidheated-liquid chamber (74), and that is coupled in series with saidpressure reducing valve (78) between said mains supply (84) and saidliquid source for heating liquid received from said mains supply (84).